Fluid-power hammer.



R. W. NAZEL.

FLUID POWER HAMMER.

APPLICATION FILED JULY 7. 1912.

Patented June 4, 1918.

1 i l l l tinrrnn snares new onnicn RALPH W. NAZEL, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR IO JOHN NAZEL, OF PHILADELPHIA, PENNSYLVANIA.

FLUID-POWER HAMMER.

Specification of Letters Patent.

Patented June at, 1918.

Application filed July 7, 1917. Serial No. 179,150.

To all whom it may concern:

Be it known that I, RALPH W. NAZEL, a citizen of the United States, residing in the city of Philadelphia, county of PhiladeL phia, and State of Pennsylvania, have invented certain Improvements in Fluid- Power Hammers, of which the following is a specification.

My invention relates especially to improved means for cushioning the ram as it approaches the limit of its reverse movement.

My improved means are simple, durable and efiicient, effecting the desired absorption. of the shock by trapping fluid to form a cushion at a predetermined point in the reverse movement and providing for the free admission of air to the cushion chamber to counteract the tendency to form an obstructing vacuum in the forward movement of the ram.

In the accompanying drawing, Figure 1 is a part sectional elevation of a fluid power hammer embodying my improvements and Fig. 2 is a sectional view of details of the construction in a second position.

- and forming a head for the cylinder 3., the

reduced bottom or stem 11 of the cylinder 9 containing the ports 12 and 13 in communication with the atmosphere. A check valve 14, held in the port 13 by the perforated retainer 15, is adapted for controlling this port.

A hollow ram 16 is movable through the collar 17 fixed to the bottom of the cylinder 3, the interior ofthe ram being adapted to forces air through the passage 5 beneath the piston or ram head 18, the air above the ram head escaping through the passage l, the ram 16 rises freely until the stem 11 on the stationary cylinder 9 enters the corresponding recess 19 in the bottom of the ram. The escape of air from the ram, which had taken place freely through the ports 12, is now checked since the stem 11 closes the recess 19 and the pressure of the air' compressed in this recess elevates the ball 14 to close the port 13, thus trapping the air in the recess and gradually stopping by means of the air cushion further upward movement of the ram.

In the downward movement of the ram 16, the upward movement of the piston 6 forces air through the passage 4 into the cylinder 8 above the piston 18, air escaping from this cylinder through the passage 5 beneath this piston.

When the air compressed in the recess 19, which initially assists in starting the ram down, is sufiiciently expanded by the clownward movement, the ball 14 falls and opens the port 13, preventing the formation of a vacuum which would obstruct the desired downward movement.

Having described my invention, I claim:

1. In a fluid power hammer, a work cylinder and a guide cylinder having an end fixed in said work cylinder, said guide cyl inder having a free reduced end in said work cylinder and a port in said reduced end, in combination with a hollow ram movable in said work cylinder on said guide cylinder and having a reduced end recess adapted to be closed by said reduced end and thereby cut off from communication with said port.

2. In a fluid power hammer, a work cylinder and a hollow guide cylinder therein, said guide cylinder having a reduced end containing a lateral port communicating freely with the atmosphere, in combination with a hollow ram movable in said work cylinder on said guide cylinder'and having an end recess adapted to communicate with said port, to fit said reduced end, and to be cut off from communication with said port by said reduced end.

3. In a fluid power hammer, a Work cylsaid ram having a recess adapted to cominder, a hollow guide cylinder therein, said municate with said ports, to fit said reduced guide cylinder having ports communicating end and to be cut off from communication 1 with the atmosphere and a check'valve for With one of said ports by said reduced end.

5 controlling one of said poi-ts, in combinai- In testimonywhereof I have hereunto set tion with a hollow ram movable in said my name this 5th day of July, 1917. work cylinder and on said guide c linder; RALPH W. NAZEL;

Copies of this patent may be obtained for fiye cents each, by addressing the Commissioner of Patents, Washington, D. 01 

